摘要
采用室内实验方法研究了Cr(VI)在黄棕壤和红壤上的吸附等温线以及平衡溶液酸度、不同浓度柠檬酸和EDTA存在时对Cr(Ⅵ)在2种土壤上吸附过程的影响。结果发现,柠檬酸的存在均降低了Cr(Ⅵ)在2种土壤上的吸附量,表现出明显的竞争吸附;而EDTA对Cr(Ⅵ)在黄棕壤上的吸附几乎没有影响,而对其在红壤上的吸附有抑制作用。该研究结果将有助于理解Cr(Ⅵ)的土壤溶液平衡过程。
Chromium exists in e nvironment in t wo major valences as Cr (Ⅲ)and Cr (Ⅵ),and the latter one is very hazardous to human beings.In China,soil Cr pollu tion is severe,mainl y caused by tannery,papermaking and mining.Once Cr enters soil,it will react with soil constitutes in diffe rent physical and chemical manners.Low molecular weight organic acids widely distributed in soil will affect Cr (Ⅵ)behavior i n soil,but very limited studies are performed on the work.The a dsorption isot herms of Cr (Ⅵ)in yellow brown soil and red earth were investigated under dif ferent solution pH,t he coexistence of citric acid and EDTA conditions.Cr (Ⅵ )adsorption quantity in the red earth was higher than that in the yellow bro wn soil,which maybe attributed to th e high content of Fe and Al oxides in the re d earth rather than the yellow brown soil;while,Cr (Ⅵ)adsorbed in the yello w brown soil was desorbed more difficultly than that in the red earth.The highe r the solution pH,the less the Cr (Ⅵ)adsorption in soil.Citric acid redu ce d Cr (Ⅵ)adsorption quantity in the two soils,while EDTA reduced Cr (Ⅵ)ads orption quantity in the red earth but had no effect in the yellow brown soil.Cr (Ⅵ)adsorption quantity reduced at firs t,then increased,with the increase of citric acid to Cr (Ⅵ)ratios in the yellow brown soil solutions,because hi gh c oncentrations of citric acid possib ly resulted in the reduction of Cr (Ⅵ ).EDTA had no effect on Cr (Ⅵ)adsorption even in the increased con centrati on in the yellow brown soil s olution,since the low contents of Fe and Al oxide s not suitable for the EDTAadsorption,while Cr (Ⅵ)adsorption quantity decrea sed grad ually with the increase of citric acid or EDTA in the red earth solutio n.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2004年第4期710-713,共4页
Journal of Agro-Environment Science
基金
国家自然科学基金(20207010)
国家重点基础发展规划项目(2002CB410808)
关键词
有机酸
Cr(Ⅵ)
黄棕壤
红壤
吸附
organic acid
Cr (Ⅵ)
yellow brown soil
red earth
adsorption
